Sirius.server.localserver.history

Class HistoryServer

java.lang.Object

Sirius.server.AbstractShutdownable

Sirius.server.Shutdown

Sirius.server.localserver.history.HistoryServer

All Implemented Interfaces:

Serializable, Shutdownable

public final class HistoryServer
extends Shutdown

DOCUMENT ME!

Version:

$Revision$, $Date$

Author:

martin.scholl@cismet.de

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	JSON_DELETED

Fields inherited from class Sirius.server.Shutdown

PRIORITY_EARLIER, PRIORITY_EARLIEST, PRIORITY_LATER, PRIORITY_LATEST, PRIORITY_NORMAL

Constructor Summary

Constructors

Constructor and Description
HistoryServer(DBServer server) Creates a new HistoryServer object.

Method Summary

Modifier and Type	Method and Description
void	enqueueEntry(MetaObject mo, User user, Date timestamp) Returns rather fast and only enqueues the entry instead of actually creating the history entry.
HistoryObject[]	getHistory(int classId, int objectId, User usr, int elements) Returns the history of the given object of the given class.
boolean	hasHistory(MetaObject mo) Determines if there are any history entries for the given MetaObject.
void	initHistory(MetaObject mo, User usr, Date timestamp) Creates an initial entry for the given MetaObject.

Methods inherited from class Sirius.server.Shutdown

addShutdown, addShutdown, createShutdown, internalShutdown, removeShutdown

Methods inherited from class Sirius.server.AbstractShutdownable

isDown, shutdown

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

JSON_DELETED

public static final String JSON_DELETED

See Also:

Constant Field Values

Constructor Detail

HistoryServer

public HistoryServer(DBServer server)

Creates a new HistoryServer object.

Parameters:

server - the DBServer that is responsible for delivering classes, connections and objects

Throws:

IllegalArgumentException - if the given DBServer instance is null

Method Detail

getHistory

public HistoryObject[] getHistory(int classId,
                                  int objectId,
                                  User usr,
                                  int elements)
                           throws HistoryException

Returns the history of the given object of the given class. The number of historic elements that will be retrieved depends on the given element count and the amount of available historic elements. Resolution strategy:

• elements < 1: order by timestamp
• elements > 0: order by timestamp limit elements

This operation initialises the history of the object if its class is history enabled and it is not initialised yet. Thus this operation never returns an empty list but always at least one object in case of a history enabled status.

Parameters:

classId - the id of the desired class

objectId - the id of the object of the desired class

usr - the User that requests the history

elements - the number of historic elements to be retrieved or an int < 1 to retrieve all available elements

Returns:

the historic objects or null if the class is not history enabled

Throws:

HistoryException -

• if the given User is null
• if the classcache did not provide a class (e.g. because the classid is unknown/invalid)
• if the user does not have read permissions for given class
• if any other error occurs

See Also:

ClassAttribute.HISTORY_ENABLED, initHistory(Sirius.server.middleware.types.MetaObject, Sirius.server.newuser.User, java.util.Date)

hasHistory

public boolean hasHistory(MetaObject mo)
                   throws HistoryException

Determines if there are any history entries for the given MetaObject. This operation does not care about the ClassAttribute.HISTORY_ENABLED flag. It simply looks up whether there are entries in the database or not.
NOTE: This operation does not initialise the history!

IMPORTANT: This operation should not be exposed directly through server api/middleware since it is not protected by permission check

Parameters:

mo - the MetaObject to check

Returns:

true if there is at least one historic entry, false otherwise

Throws:

HistoryException - if the given MetaObject is null or any error occurs during database query

initHistory

public void initHistory(MetaObject mo,
                        User usr,
                        Date timestamp)
                 throws HistoryException

Creates an initial entry for the given MetaObject. Basically it does the same as the enqueueEntry(Sirius.server.middleware.types.MetaObject, Sirius.server.newuser.User, java.util.Date) operation except that it checks whether there is an entry already, actually runs the insertion if not and throws an exception if an error occured.

Parameters:

mo - the metaobject that shall be historicised

usr - the user that implicitely creates the history entry

timestamp - the timestamp when the entry is created

Throws:

HistoryException - if the given MetaObject is null or the given Date is null or an error occurred during history insertion

See Also:

enqueueEntry(Sirius.server.middleware.types.MetaObject, Sirius.server.newuser.User, java.util.Date)

enqueueEntry

public void enqueueEntry(MetaObject mo,
                         User user,
                         Date timestamp)

Returns rather fast and only enqueues the entry instead of actually creating the history entry. If the MetaObject's MetaClass is not history enabled at all nothing will be done. If the "anonymous" option is enabled the given user is ignored.

NOTE: This operation does not initialise the history!

Parameters:

mo - the metaobject that shall be historicised

user - the user that implicitely creates the history entry

timestamp - the timestamp when the entry is created

See Also:

ClassAttribute.HISTORY_ENABLED, ClassAttribute.HISTORY_OPTION_ANONYMOUS